Study On Involute Of Variable Circle Radii In Scroll Compressor

As a new volumetric fluid machinery,scroll compressor is regarded as another new typedisplacement compressor after reciprocating compressor, rotor compressor and helical-lobecompressor. It has characteristics of high efficiency small bulk, light weight, low noise,simple structure and working smoothly etc., is widely used in refrigeration andair-conditioning, power engineering, communications and transportation etc.Scroll compressor profile line study is an important issue in scroll compressor study; itinvolves not only performance, but also significant affection on the processing costs. In thispaper, profile line equation, stroke volume, length of profile line and curvature were derivedin detail, which laid the foundation for correct design of scroll compressor and theestablishment of the profile lines'mathematical model. The mutual relationship was obtainedthrough the comparison of the commonly used simple profile lines'different forms ofexpression. The variation characteristics of volumetric rate and the transition characteristics ofprofile lines were obtained through the analysis of common combination profile lines whichwere connected by simple profile lines.The types of scroll compressor profiles include: involute of circle, line involute,equilateral polygon involute, parallelogram involute, achimedean spiral, variable circle radiiinvolute, envelope profile and general utilization profile etc. Hybrid profile is such a profilebasing on the same vortex tooth,and different types of profiles are adopted to connect into thesmoothness one. Hybrid profiles based on several of common and general utilization profilesare usually variable circle radii profiles. In order to express the advantage of different typesprofiles, the suction, compressed, and exhaust are taken into consider. With hybrid profiles,the vortex plate area utilization rate, displacement and compression ratio of scroll compressorare increased, and the length and width of vortex tooth profile are reduced.Variable circle radii involute profiles were analyzed in this paper, with the theory ofdifferential geometry conjugate curved surface, the feasibility of variable circle radii involuteusing as scroll compressor profiles were proved, the basic characteristics of the profile wasdiscussed, and the basic equations were deduced also. In addition, working chamber volume of scroll formed with variable circle radii involute profile was calculated and gas forces ofvortex tooth were analyzed.